The poem takes place during the reign of Charlemagne. He's conquered all of Spain except for the holdout city of Saragossa under King Marsile whom the poem describes as worshiping Mohammed and Apollo. Marsile asks his advisers on how he should respond to Charlemagne's aggression, and they argue that becoming his vassal would offer the most favorable terms. Marsile agrees and sends ambassadors to Charlemagne. Upon hearing Marsile's offer of vassalage, Charlemagne consults with his most trusted knights. He's inclined to reject the offer based upon earlier examples of pagan treachery. His nephew Roland reminds him that he has a duty to avenge his vassals who fell in battle against the pagans. Roland's step-father Ganelon urges him to accept Marsile's terms and the other knights agree. Roland volunteers to be the ambassador at first, but later nominates Ganelon. Ganelon reacts angrily to his appointment and uses it as an opportunity to exact revenge. He comes to Marsile's court and tells the pagan king that if Roland is killed in battle, Charlemagne will lose the heart for further warfare. He promises to arrange it so Roland leads the rear guard of the Frankish army so that Marsile's army can ambush them and destroy them in detail.
What follows is a long roll call of Marsile's commanders as they each promise to visit numerous and varied grotesqueries upon the Franks. Roland's companion Oliver is the first to realize that battle is upon them. When he tells Roland, he replies, "And may God grant it to us." Roland offers this reason for joining battle: "The pagans are wrong and the Christians are right."
What follows is a long and gruesome battle where the pagans' numbers soon tell. Roland begins the battle by refusing to call for aid by blowing the oliphaunt horn as it would dishonor him and his family. At the point of death, he changes his mind. He dies while Charlemagne and his army are en route and the emperor is devastated by his nephew's death. Marsile, mortally wounded in his battle with Roland's rearguard, calls on Baligant, emir of Babylon, for help. Baligant and Charlemange's forces are joined in an even bloodier battle. The two monarchs face off in single combat. Each calls upon the other to forsake their religion and then there will be peace. Both emphatically reject the others' terms. Only death will stay their hand. Charlemagne is protected from a mortal blow by St. Gabriel the Archangel, and he slays Baligant. The victorious Franks return home, Marsile's queen converts to Christianity, and Ganelon is executed for his treachery by being pulled apart by horses.
Chivalry is regularly mocked in the manosphere. What began as a code of conduct for warriors of the First Crusade quickly devolved into literal white knighting by the late Middle Ages. By the Renaissance, chivalry had become little more than chick lit. Even the venerable Catholic Encyclopedia of 1917 took a dim view of chivalry:
The amorous character of the new literature had contributed not a little to deflect chivalry from its original ideal. Under the influence of the romances love now became the mainspring of chivalry. As a consequence there arose a new type of chevalier, vowed to the service of some noble lady, who could even be another man's wife. This idol of his heart was to be worshiped at a distance. Unfortunately, notwithstanding the obligations imposed upon the knightly lover, these extravagant fancies often led to lamentable results.The Song of Roland portrays the older view of chivalry. Roland and his companions absolutely refused to quit even in the face of certain death. They repeatedly refuse to call for help because recoiling in the face of an enemy was regarded by them as worse than death. That Christianity was right and paganism wrong was reason enough to fight to the bitter end. Their faith tempered their bloodlust somewhat, but warfare was the way of life. To be a great warrior was the highest aspiration a man could pursue. To fight for the king and for Christ was the noblest vocation a man could have in the world. If that weren't enough, one of Roland's companions was Archbishop Turpin. A man of the cloth took up a mace and caved in pagan skulls alongside his flock. He too is slain on the battlefield but spends his last moments of life blessing and absolving his comrades.
The feminization of Christianity since the 19th century is too long a topic for one post. The best book length treatment of the subject I've read is The Church Impotent, by Leon Podles, available for free on his website. It's a mistake to think of Christianity as nothing but a tool for shaping culture. Yes, Christendom inspired the first universities and countless hospitals, orphanages, artwork, scientific work, archaeology, and all the rest. But even if she hadn't, I'd still be obligated to believe Christianity because it's true. That's the only reason anyone should believe anything. Christianity influences culture to be sure, but it's our means of communing with the divine before all else. Frenchmen and Germans of the 11th century shared a religion, and shared a monarch in the person of Charlemagne, but they remained different from one another.
The Church Militant on earth cannot help but be influenced by the times as it is made up of living human beings. The Church Triumphant in heaven is always the same. The truths revealed by God do not and cannot change. Back then you had not only the military orders such as the Knights Templar, but occasionally priests or bishops would take up arms. Pope Julius II personally led troops in battle. That's not to say he was right to do so, but the Church on earth can vary widely in its, ah, pastoral practice from time to time and place to place.
It's unfortunately the case today that the Church is influenced more by the culture than she influences it. The German heretics such as Kasper aren't operating in a vacuum. They are secular because their people are secular. Instead of seeking to bring practice in line with doctrine, they want to jettison doctrine to accommodate practice. We live in a feminist world and many Christians have adopted the feminist view wholesale. We gloss over, explain away, or ignore those parts of Scripture which are offensive to feminist ears.
Other denizens of the manosphere err when they attribute the feminization of Christianity to something intrinsic to the faith itself. The life of St. Ignatius of Loyola alone should dissuade anyone but the most hardcore secularists that Christianity is for wimps. The fault isn't with Christianity, but with us. We are the ones who have become weak and effeminate. The manosphere is at its best when it encourages self-improvement. We're not going to change the modern culture of Christianity unless we change ourselves first.